The table below shows a summary of the occurrence records for the taxon. A record “with coordinates” is one that has a complete set of latitude and longitude values associated with it, which could be used for distribution modeling, the preliminary threat assessment, and the conservation gap analysis. For this analysis, such records with coordinates were confined to those falling within the target native area, i.e. native states/administrative areas within the United States (including its territories), Canada, Mexico, and the Caribbean islands, as listed per taxon in USDA ARS GRIN Global Taxonomy (2020). In preparation for the conservation gap analyses, we classified each record based on whether it was an existing ex situ sample from a genebank or botanic garden (labeled G, as most records were from genebanks), or a reference observation (labeled H, as most of these records were from herbaria).
The table below shows the ecogeographic variables listed in order of importance based on the occurrence dataset, including whether or not they were used for distribution modeling, following the variable selection process.
For each taxon with at least 25 distinct coordinates in the target spatial area, the modeled distribution was calculated as the median of ten MaxEnt model replicates (K = 10), using linear, quadratic, product, and hinge features, with a regularization parameter ß=1.0. For taxa with 8-24 distinct coordinates, the median of six replicates (K = 6) was calculated, and for taxa with 3-7 distinct coordinates, the median of three replicates (K = 3) was calculated. Model runs for taxa where MaxEnt failed within these established groupings were rerun in fewer replicate categories. Taxa with fewer than 3 distinct coordinates were not modeled. The table below shows the statistical results for each replicate.
The median result across the replicates is shown below. To be considered an accurate and stable model (see the field “Valid”), we are looking for an AUC >= 0.7; SDAUC < 0.15; and ASD15 <= 10.
The map below shows the median spatial result from the species distribution model runs. Values in the key refer to the probability of occurrence. The occurrences used in the modeling process are represented by dots, distinguishing between G and H records (as available), and the attribute data associated with the points can be viewed by clicking on the dots. The background shows the target native area (i.e. the occupied native country-ecoregion area).
The map below shows the standard deviation result across species distribution model replicates. Areas with a high standard deviation imply a limited agreement between the replicates. This is most likely to occur in areas with low sample (occurrence point) density.
The map below shows the threshold (binary presence-absence) result from the species distribution modeling. This is the map used to perform the conservation gap analyses and to create the richness maps across taxa. The background shows the target native area (i.e. the occupied native country-ecoregion area). Predicted presence is displayed in green.
We calculated the extent of occurrence (EOO) and area of occupancy (AOO), adapted from the IUCN Red List criteria (AOO cell size 4 km2), using the occurrence data with coordinates in the native area of the taxon. Taxa are classified per metric and in combination, as Critically Endangered (CR) where EOO < 100 km2 or AOO < 10 km2, Endangered (EN) where 100 km2 < EOO < 5000 km2 or 10 km2 < AOO < 500 km2, Vulnerable (VU) where 5000 km2 < EOO < 20,000 km2 or 500 km2 < AOO < 2000 km2, Possible Near Threatened (NT) where 20,000 km2 > EOO < 45,000 km2 or 2000 km2 < AOO < 4500 km2, and Least Concern (LC) where EOO ≥ 45,000 km2 and AOO ≥ 4500 km2. Taxa with fewer than three distinct coordinates were automatically classified as CR.
The table below shows the ex situ conservation gap analysis summary. The sampling representativeness score ex situ (SRSex) calculates the ratio of germplasm accessions (G) available in ex situ repositories to reference (H) records for each taxon, making use of all compiled records, regardless of whether they include coordinates. The geographical representativeness score ex situ (GRSex) uses buffers of 50 km radius created around each G collection coordinate point to estimate geographic areas already well collected within the distribution models of each taxon, and then calculates the proportion of the distribution model covered by these buffers. The ecological representativeness score ex situ (ERSex) calculates the proportion of terrestrial ecoregions represented within the G buffered areas out of the total number of ecoregions occupied by the distribution model. A final conservation score for ex situ (FCSex) was derived by calculating the average of the three ex situ conservation metrics. All of the conservation metrics are on a scale from 0-100, with 0 = poor conservation and 100 = comprehensive protection. The FCSex is used to categorize species, with urgent priority (UP) for further conservation action assigned when FCSex < 25, high priority (HP) where 25 ≤ FCSex < 50, medium priority (MP) where 50 ≤ FCSex < 75, and low priority (LP) for taxa whose FCSex ≥75.
The map below shows the potential distribution (threshold map), with previous germplasm collection points surrounded by a 50 km buffer overlaid. Only germplasm (G) points are displayed on the map.
0 = Native area (area of ecoregions within countries where taxon has been observed in the field)
1 = Potential distribution
2 = G buffer (area where ex situ conservation is considered to have been accomplished)
The map below shows the potential distribution, highlighting ecoregions from which no G occurrences have been collected.
0 = Native area (area of ecoregions within countries where taxon has been observed in the field)
1 = area of potential distribution with ecoregions that have been collected for ex situ conservation
Greater than 1 = area of potential distribution with ecoregions that have not been collected for ex situ conservation, identifying each ecoregion
The table below shows the in situ conservation gap analysis summary. The sampling representativeness score in situ (SRSin) calculates the proportion of all occurrences of a taxon within its predicted distribution that fall within a protected area. The geographical representativeness score in situ (GRSin) compares the area (in km2) of the distribution model located within protected areas versus the total area of the model. The ecological representativeness score in situ (ERSin) calculates the proportion of ecoregions encompassed within the range of the taxon located inside protected areas to the ecoregions encompassed within the total area of the distribution model. A final conservation score for in situ (FCSin) was derived by calculating the average of the three in situ conservation metrics. All of the conservation metrics are on a scale from 0-100, with 0 = poor conservation and 100 = comprehensive protection. The FCSin is used to categorize species, with urgent priority (UP) for further conservation action assigned when FCSin < 25, high priority (HP) where 25 ≤ FCSin < 50, medium priority (MP) where 50 ≤ FCSin < 75, and low priority (LP) for taxa whose FCSin ≥75.
The map below shows occurrences within the predicted distribution that are outside of protected areas. Values are summarized by count per cell.
Predicted Distribution = 0
1 and above = Number of cccurrences present at a location outside of a protected area
Protected areas are displayed in purple
The map below shows the potential distribution (threshold map), with distribution occurring within existing protected areas highlighted.
0 = Native area (area of ecoregions within countries where taxon has been observed in the field)
1 = Potential distribution
2 = Protected areas within potential distribution
The map below shows the potential distribution, highlighting ecoregions in which no protected areas are present.
0 = Native area (area of ecoregions within countries where taxon has been observed in the field)
1 = area of potential distribution with ecoregions that have been conserved in protected areas
Greater than 1 = area of potential distribution with ecoregions that have not been conserved in protected areas, identifying each ecoregion
The table below shows the combined ex situ and in situ conservation gap analysis metrics. Minimum and maximum scores are identified, and a combined final conservation score (FCSc-mean) was calculated by averaging the final ex situ (FCSex) and in situ (FCSin) scores. The taxon is then categorized, with urgent priority (UP) for further conservation action assigned when FCS < 25, high priority (HP) where 25 ≤ FCS < 50, medium priority (MP) where 50 ≤ FCS < 75, and low priority (LP) for taxa whose FCS ≥75.
This document was last updated on 2020-08-17